Darwin did not “shelf” his findings, in the sense of stopping work. He just spent decades gathering additional mountains of evidence because he was worried that opponents would spring up and he wanted to make sure everything was watertight.

Then despite his overwhelming evidence, exactly what he feared still happened (and still happens today)

I didn't mean to imply he stopped working on it entirely, but he definitely put off publishing as long as he could because he was (reasonably) worried about what would happen afterwards.

Welp, FWIW Newton did the same thing with Calculus.

The Leibniz independently invented many of these ideas, plus the notation we use to this day, and published first.

Didn't stop Newton for starting a war with Leibniz over whoddunit, though.